The subject matter disclosed herein relates to systems and methods for on-line calibration and compensation of current transformers.
Current transformers are devices capable of sensing changes in the current flowing through a cable or a collection of cables and producing voltage proportional to that variation. When an alternating current is measured, the output voltage from the current transformer is proportional to the amplitude of that current. As such, in alternating current applications, current transformers can be used as current sensors. Proper calibration of a current transformer allows it to be used as a quantitative sensor.
Due to changes in the material from natural usage or from environmental conditions, the gains identified during calibration may change over time. As a result, to maintain accuracy as a quantitative sensor and to allow compensation based on measurements derived from the current transformer, subsequent calibrations may be periodically required. However, such calibrations typically require equipment downtime, which may be undesirable and/or expensive in an operational environment where equipment uptime is desired.